1. Field of the Invention
The present invention relates to the combination of a USB connector and a MicroSD flash card connector in a common housing. The MicroSD flash card connector can be used with standard MicroSD flash cards. The connectors can be one on top of the other or side-by-side to each other in the common housing which can include shielding.
2. Description of Related Art
USB connectors are electrical connectors that are used for networking and computer products, such as desk-top computers, laptops, tablets, cellphones, and other products which require connections to peripheral devices. USB connectors are used in many industries.
Universal Serial Bus (USB) is an industry standard developed in the mid-1990's that defines the cables, connectors and communications protocols used in a bus for connection, communication and power supply between computers and electronic devices.
USB was designed to standardize the connection of computer peripherals including keyboards, pointing devices, digital cameras, printers, portable media players, disk drives and network adapters to personal computers both to communicate and to supply electric power. It has become commonplace on other devices, such as smartphones, PDAs and video game consoles. USB has effectively replaced a variety of earlier interfaces, such as serial and parallel ports, as well as separate power chargers for portable devices.
The USB standard evolved through several versions before its official release in 1996. The first version USB 1 (Full Speed) is one type of USB connector. Released in January 1996, USB 1 specified data rates of 1.5 Mb/s (Low-Bandwidth) and 12 Mb/s (Full-Bandwidth). It did not allow for extension cables or pass-through monitors (due to timing and power limitations). Few USB devices made it to market until USB 1.1, released in August 1998, which fixed problems identified in USB 1.0, mostly relating to hubs. USB 1.1 was the earliest revision that was widely adopted.
The second version was USB 2.0 (High Speed) USB 2.0. Released in April 2000, USB 2.0 added higher maximum signaling rate of 480 Mbit/s (effective throughput up to 35 MB/s or 280 Mbit/s) (now called “Hi-Speed”). Further modifications to the USB specification have been done via Engineering Change Notices (ECN). The most important of these ECNs were included into the USB 2.0 specification package available from USB.org.
The third version, USB 3.0, was released in November 2008. The USB 3.0 standard defines a new “SuperSpeed” mode with a raw signaling speed of 5 Gbit/s and a usable data rate of up to 4 Gbit/s. USB 3.0 reduces the time required for data transmission, therefore reducing power consumption, and it is backward compatible with USB 2.0. The USB 3.0 Promoter Group announced on 17 Nov. 2008 that the specification of version 3.0 had been completed and had made the transition to the USB Implementers Forum (USB-IF), the managing body of USB specifications. This move effectively opened the specification to hardware developers for implementation in products. The new “SuperSpeed” bus provides a fourth transfer mode at 5.0 Gbit/s (raw data rate), in addition to the modes supported by earlier versions. As with previous USB versions, USB 3.0 ports come in low-power and high-power variants, providing 150 mA and 900 mA respectively while simultaneously transmitting data at SuperSpeed rates. Additionally, there is a Battery Charging Specification (Version 1.2—December 2010), which increases the power handling capability to 1.5 A but does not allow concurrent data transmission. The Battery Charging Specification requires that the physical ports themselves be capable of handling 5 A of current but the specification limits the maximum current drawn to 1.5 A.
A January 2013 press release from the USB group reveals plans to update USB 3 to 10 Gbit/s to put it on par with other type of emerging connectors like the Thunderbolt® connector. Thunderbolt® is a U.S. registered trademark of Apple, Inc. of Cupertino, Calif., Reg. No. 1,078,726.
There are several types of USB connectors, including some recently added ones. The original USB specification includes Standard-A and Standard-B plugs (FIG. 2) and receptacles; the -B connector enabled cabling to be plugged at both ends while preventing users from connecting one computer receptacle to another. FIGS. 3A-3F show different types of USB-A and -B connectors including standard, mini, and micro types.
The USB type-A plug (FIG. 3A) is a flattened rectangle that inserts into a “downstream-port” receptacle on the USB host or a hub, and carries both power and data. The USB type-A plug is frequently seen on cables that are permanently attached to a device, such as one connecting a keyboard or mouse to the computer via USB connection.
A USB type-B receptacle (FIG. 3B) has a square shape with beveled exterior corners and is configured to mate with an “upstream receptacle” on a device that uses a removable cable, e.g. a printer. On some devices, the USB type-B receptacle has no data connections, being used solely for accepting power from the upstream device.
The USB Mini-A plugs (FIG. 3C) and USB Mini-B receptacles (FIG. 3D) are approximately 3 by 7 mm. These mini-USB plugs and receptacles have a similar width and approximately half the thickness of USB type-A plugs and -B receptacles, enabling their integration into thinner portable devices.
USB Micro-A (FIG. 3E) and Micro-B (FIG. 3F) connectors were announced by the USB-IF on 4 Jan. 2007. The Mini-A plug and the Mini-B receptacle were deprecated on 23 May 2007. While many currently available devices and cables still use Mini connectors, the newer Micro connectors were being widely adopted as of December 2010. The thinner USB Micro-A and -B connectors are intended to replace the Mini USB connectors in new devices including smartphones, personal digital assistants, and cameras.
USB connectors are inexpensive, relatively simple to assemble, and easy to plug and unplug. A USB connector typically has a plastic body, with no locking mechanism to lock the male and female into place when connected.
USB female connectors (or receptacles) have socket houses for insertion of male USB plugs to form a connection. The housings are available in many configurations including a one port, multiple ports in a horizontal row, vertical, and stackable connectors which are stacked rows of USB connectors.
MicroSD is a very small removable flash memory card, used, for example, with mobile phones, tablets, laptops and desktop computers to store content. It is the smallest flash memory card currently on the market. It measures just 5 mm×11 mm×0.7 mm, making it perfect for mobile phone and tablet computer use. When users want to insert the card into a MicroSD card connector, they simply slide the card into the connector opening and it locks into place.
Although MicroSD cards are physically very small, they can store large amounts of data. MicroSD cards are available with flash storage capacities ranging from 128 MB up to 4 GB, using a storage density of 34 GB/cm3. There are different formats on MicroSD cards used to store the data, including the SDHC format. Current capacities are 4 GB, 8 GB, 16 GB, 32 GB, 64 GB and 128 GB. This capacity may increase in the future and stay in the same MicroSD form factor.
SDHC stands for Secure Digital High Capacity. SDHC cards, as the name suggests, provide higher storage capacity in a card with the same form factor as a normal Secure Digital (SD) card. SDHC cards first appeared in 2006. SDHC cards are generally formatted with the Fat32 file system. SDHC cards have a fixed sector size of 512 bytes.
The SD Card Association (SDA) has placed a limit of 32 GB on SDHC capacity, while technically speaking it could support up to 2 terabytes (TB) of storage. SDHC cards emerging onto the market created considerable consumer confusion as normal SD cards are used for many portable devices including digital cameras, camcorders, game systems, MP3 players and other electronic devices. SDHC cards are also graded by speed in three classes. Generally speaking, Class 2 offers 2 MB/sec, Class 4 offers 4 MB/sec and Class 6 offers 6 MB/sec.